Data storage systems are arrangements of hardware and software that include storage processors coupled to arrays of non-volatile storage devices, such as magnetic disk drives, electronic flash drives, and/or optical drives and the like. The storage processors service storage requests, arriving from host machines (“hosts”), which specify files or other data elements to be written, read, created, or deleted, for example. Software running on the storage processors manages incoming storage requests and performs various data processing tasks to organize and secure the data elements stored on the non-volatile storage devices.
Data storage systems commonly store file systems that can be accessed by hosts over a network. For example, clients of host machines can store their files and directories in file systems on a data storage system, which acts as a file server or NAS (Network Attached Storage) server. File systems are commonly denominated in blocks, where a “block” is the smallest unit of storage that can be allocated in a file system. Common block sizes are 8 KB, for example, although block sizes may vary.